R4-MOT Balancing Trimmer?

[wlaidlaw]

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I have just acquired one of the original brochures for my R4-MOT camera. On the page with all the functions and controls shown, there is a control positioned next to the exposure mode control which is shown as "The Balancing Trimmer" which ensures identical exposures in identical lighting conditions. The manual I have is for the later R4 rather than the R4-MOT and this manual is wholly silent about the balancing trimmer. What is this control and what exactly does it do? Anyone know? It is not just another word for exposure compensation, as that is on the ISO setting dial on the other side of the top of the camera. On the image below of the brochure, the Balancing Trimmer is item #2. Exposure Compensation is item #15. 

Wilson

 

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Edited March 16, 2021 by wlaidlaw

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[earleygallery]

Hi Wilson,

The diagram appears to be showing the internal circuitry (there's no 'control' where the pointers are on the camera itself). I can't imagine what they actually mean - Leica's translations aren't always accurate. Something like the electrics will always round up or always round down to the nearest step in shutter speed or aperture (or something like that!).

[andrew01]

Perhaps it is something to do with the final exposure check after the lens stops down?  This is a feature designed to account for the fact that the stopped down aperture might not perfectly match the specified value.

[wlaidlaw]

I suspect it may just be a sales department speak and really means nothing at all. 

Wilson

[masjah]

 

Wilson

I think that including this was a confusion just because it is an "exploded view". The pointer arrow divides into two, and you can see what look like two skeletal preset potentiometers. They are probably no more and no less than adjustment pots to set up the metering circuits, which, being analogue in those days, will be subject to component tolerance variations. I would be more surprised if the camera did not contain one or two of these. Unless the metering is out because components have changed in value due to ageing, I would just forget about them. If the metering does need adjustment, you would need to know exactly how to do it anyway, so would best be left to those who know (assuming it's worth the cost).

[wlaidlaw]

John, 

To my surprise, after taking the top off this apparently dead camera, which was a freebie with the 500MR Telyt and cleaning all the contacts on the mode and ISO switches, the metering has proved to be very accurate. 

Wilson

[GregNski]

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"Trimmer pot" is common electric-speak for a potentiometer, so almost certainly masjah is correct when he calls them "adjustment pots".